Saeed, M., and M. Z. Ali. “OPTICAL TAMM STATES AT INTERFACES OF DIFFERENT PERIODIC MEDIA CONTAINING SINGLE AND DOUBLE NEGATIVE MATERIAL LAYERS”. The Nucleus, vol. 50, no. 3, Sept. 2013, pp. 289-93, http://www.thenucleuspak.org.pk/index.php/Nucleus/article/view/758.